Undertale "Theory" 1:

Chara actually looked Like Frisk-

(I know I've said this one before but in other Books)

For this theory I'm on the subject of why Asriel mistook Frisk for Chara. But first let's compare the sprites between Frisk and Chara.

Really different, right?
Well from what we are shown, humans are represented with the same general shape. Looking at the sprites they DO look way different. Different Skin shades, slightly different hair colors, clothes etc. So why would Asriel mistake Frisk for Chara?

Well this is my Theory:

Chara actually Looked like Frisk

Ok I know I know

"But Shiny! They look NOTHING alike!"

Well look at this screenshot of the story before the Title screen.

Humans are represented like this. Because that's all Monsters remember, or... What they have seen with Humans look like. The humans in the Village in the story may have been Tribe-like (hence the spear) and most tribes have certain features that kept to their beliefs (Ex: Native Americans For them long hair is not a stylistic concern, but is a religious issue. For many Native Americans having long hair is a symbol of tribal religious traditions which teach that hair is only to be cut when one is in mourning for the death of a close relative)

So this could have been the case with Chara.

Asriel States that Chara jumped down for a Not-So-Happy Reason. So maybe she had Cut her hair for her death in the Underground. Or it was a Religious thing for her Village. Depending on your Views, it could be the same for Frisk, or a strange coincidence.

So with that, let's get to the rest of Chara.

This can actually be explained with one common Factor: Death

Yes, that's right. What do I mean? Well

When A person Dies, their skin naturally loses color, and the funeral home generally puts makeup on the person, and injects them with a certain chemical (I forget the exact thing, but it's supposed to make their veins plump) to make the person look "alive" and preserve the body. So this could explain Chara's pale skin and rosy cheeks.

The preserving injection could also be what is "seeping" out of Chara's eyes here, because Chara might have popped a vein. Or they made it to just be creepy who knows.

And they also change the body into nicer clothes, so the clothes Chara is wearing may have been the best one she owned in life.

And to back it up more...

Why would Asriel Mistake Frisk for Chara in the first place?

He was obviously able to remember Chara, and is able to remember a lot about her. He's not a little kid (he's a kid, but he's at an age where he is able to remember things. He would not forget Chara. The First Human he saw. The Human he spent so much Time with. The Human he became best friends with. The human that became his sibling. Even in Hyperdeath form he talks about Chara, and it's been many many years. So it is Highly unlikely that he would forget easily.

So in Simpler terms:

Chara actually looked like Frisk but because of the Funeral and possibly religious things she has changed in appearance.

~

Undertale "Theory" 2:

Papyrus and Sans are both actually Gaster-

What if Gaster after he fell in the core actually became Papyrus and Sans?

And the Gaster we See in the void is the remanence of what was left of memories and code of him and put into the void and when it all mixed together it created that goop of the Gaster we know. And the reason he's violent is that he doesn't know where he is and doesn't remember who he is because all of that went to Sans, or we assume.

And how Sans and Paps connect to him is that Paps got his kind nature and his complex abilities (aka puzzles) and his hard working nature (from being the Royal scientist) from G

Sans got the Pun side and his fighting skills from G, which would also explain the Gaster Blasters and possibly his teleportation.

And as for their height that could be from the core. Paps could have gotten a positive reaction from the core while Sans got the short end of the stick

Like here we can see the Similarities between the Three. Such as Papyrus's height and head shape (Even his eye in the Overworld Sprite is lopsided, even if it is by one Pixel) , while Sans has more of Gaster's body Type rather and the thickness of his head compared to the shoulders. Even Sans's posture is slouched much like Goop Gaster's. His Lazyness might actually be Gaster's constant lack of sleep and too much hard work. So Sans Tends to treat himself "Too much" as Papyrus works too hard which could be the stress of the King counting on Gaster to be the best Royal scientist. This could also explain Papyrus's want to be in the Royal Guard, as to stay close to the Royal family like how Gaster was as the Royal Scientist.

We can also compare the FONT

Yes I am going this far.

Look at Gaster's font---Wingdings.

When translated, it's all IN CAPITAL LETERS LIKE HOW PAPYRUS SPEAKS.

And It's also a Goofy Font, much like Sans's playful nature and kid-like font.

And, to finalize this, the reason they live in Snowdin is because they still feel anxious around hot places like Hotland because of the core and the heat from it

((But anyway tell me what you think. It's like midnight, I'm tired and I feel drunk so sorry if this is just all wrong and yeah))